Method for providing and recognizing transmission mode in digital broadcasting

ABSTRACT

The present invention relates to a method for selecting an appropriate mode when performing a new broadcast, such as a 3D stereo broadcast, a UHDTV broadcast, and a multi-view broadcast, among others, while maintaining compatibility with existing broadcasting channels in an MPEG-2-TS format for transmitting and receiving digital TV, and to a method for recognizing a descriptor. To this end, the present invention suggests providing the descriptor which is related to synthesizing left and right images using the type of stream, existence of the descriptor, and a frame-compatible mode flag.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/989,320 filed on Jun. 4, 2013, which is a National Stage Applicationof PCT/KR2011/000357 filed on Jan. 18, 2011, which claims priority fromKorean Patent Application No. 10-2010-0119242 filed on Nov. 27, 2010,the contents of which are hereby incorporated by reference in theirentirety.

TECHNICAL FIELD

The present invention relates to a method of selecting a transmissionmode suitable when a new broadcast, such as a 3D stereoscopic broadcast,ultra high definition (UHD) TV broadcast, or multi-view broadcast, isprovided while maintaining compatibility with existing broadcastchannels in a MPEG-2 Transport Stream (TS) format for broadcasting usedfor digital TV transmission and reception and recognizing a descriptor.

BACKGROUND ART

In Korea, a standard of Advanced Television Systems Committee (ATSC) inNorth America, which is an 8-VSB system, was adopted as a terrestrialdigital broadcast system in November 1997. Subsequently, related coretechnology has been developed, field tests have been carried out, andtest broadcasting has been performed. Since 2001, existing analogbroadcasting and digital broadcasting have been simultaneouslyperformed. In 2012, however, switch to digital broadcasting will havebeen completed.

ATSC is an America committee developing a digital televisionbroadcasting standard or a standard of the committee. The standard ofATSC has been used as a national standard in America, Canada, Mexico,and Korea. In addition, the standard of ATSC will be adopted in othercountries, including several nations in South America. In addition toATSC, DVB, which has been developed in Europe, and ISDB of Japan areused as the standard of the digital broadcasting.

According to an ATSC digital broadcasting standard that is capable oftransmitting high-quality video, audio, and auxiliary data, data aretransmitted at a data transmission rate of 19.39 Mbps for a terrestrialbroadcast channel of 6 MHz and data are transmitted at a datatransmission rate of 38 Mbps for a cable TV channel. An ISO/IEC 13818-2MPEG-2 video standard is used as a video compression technology used inthe ATSC system. MPEG-2 MP@HL, i.e. Main Profile and High Level, is usedas a compression format. Video formats and limitations related theretoare defined.

Hereinafter, a description will be given of transmission modes which maybe used when a new broadcast, such as a 3D stereoscopic broadcast, ultrahigh definition (UHD) TV broadcast, or multi-view broadcast, is providedwhile maintaining compatibility with existing broadcast channels in aMPEG-2 TS format for broadcasting used for digital TV transmission andreception. Hereinafter, the 3D stereoscopic broadcast, UHD TV broadcast,and multi-view broadcast will be referred to as a composite imagebroadcast. Transmission modes which may be used in the MPEG-2 TS formatare divided into a frame-compatible mode and a service-compatible mode.In a case in which two transmission modes are used in a digitalbroadcast, it is necessary for a receiving end to recognize atransmission mode used by a transmission end.

DISCLOSURE Technical Problem

An object of the present invention is to provide a method of enabling areceiving system capable of processing a composite image broadcastincluding a 3D stereoscopic broadcast, ultra high definition (UHD) TVbroadcast, or multi-view broadcast to recognize reception of compositeimages such that the receiving system receives and processes thecomposite images.

Another object of the present invention is to provide a method ofenabling a receiving system not capable of processing composite imagesto disregard reception of the composite images, thereby preventingmalfunction of the receiving system.

Technical Solution

In accordance with an aspect of the present invention, the above objectsmay be accomplished by the provision of a method of providing adescriptor related to synthesis of left and right images using streamtype.

In accordance with another aspect of the present invention, there isprovided a method of providing a descriptor related to synthesis of leftand right images using presence and absence of a descriptor.

In accordance with a further aspect of the present invention, there isprovided a method of providing a descriptor related to synthesis of leftand right images using a frame-compatible mode flag.

Advantageous Effects

In a method of providing a transmission mode according to the presentinvention, it is possible to distinguish between a frame-compatible modeand a service-compatible mode using the same descriptor. In addition, itis possible to enable a receiving system capable of processing compositeimages to recognize reception of the composite images such that thereceiving system receives and processes the composite images.Furthermore, it is possible to enable a receiving system not capable ofprocessing composite images to disregard reception of the compositeimages, thereby preventing malfunction of the receiving system.

DESCRIPTION OF DRAWINGS

FIGS. 1A, 1B, 1C, and 1D are block diagrams showing a HD broadcast, 3Dbroadcast, UD broadcast, and MV broadcast, respectively;

FIG. 2A shows a frame-compatible mode and FIG. 2B shows examples ofmethods of synthesizing images to configure the frame-compatible mode;

FIG. 3 is a view showing a service-compatible mode according to anembodiment of the present invention;

FIG. 4 is a view showing the structure of a program map table (PMT)syntax according to an embodiment of the present invention;

FIG. 5 is a view showing a procedure of the PMT;

FIG. 6 is a flowchart showing a process of providing a descriptorrelated to synthesis of left and right images using stream typeaccording to an embodiment of the present invention;

FIG. 7 is a flowchart showing a process of providing a descriptorrelated to synthesis of left and right images using presence and absenceof a descriptor according to an embodiment of the present invention; and

FIG. 8 is a flowchart showing a process of providing a descriptorrelated to synthesis of left and right images using a frame-compatiblemode flag according to an embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

FIGS. 2A and 2B: Frame-compatible mode FIG. 3: Service-compatible mode

BEST MODE

The above and other aspects of the present invention will be moreclearly understood from the following detailed description of preferredembodiments taken in conjunction with the accompanying drawings.Hereinafter, the detailed description of the preferred embodiments ofthe present invention will be given to enable those skilled in the artto easily understand and reproduce the invention.

First, types of digital broadcasts will be described. Generally, digitalbroadcasts are classified into a 3-D stereoscopic broadcast, an UltraHigh Definition (UHD) TV broadcast, and a Multi-view broadcast.

FIGS. 1A, 1B, 1C, and 1D are block diagrams showing a HD broadcast, 3Dbroadcast, UD broadcast, and MV broadcast, respectively. Hereinafter, a3D stereoscopic broadcast, UHD TV broadcast, and multi-view broadcastwill be referred to as a composite image broadcast.

An HD broadcast transmits one image. However, the 3-D stereoscopicbroadcast transmits two images, the UHD broadcast transmits four images(in case of 4 k), and the multi-view broadcast transmits two or moreimages.

The 3-D stereoscopic broadcast is a method of assigning a PacketIdentifier (PID) for MPEG-2 TS to left and right images and performingmultiplexing transmission to transmit a stereo type three-dimensionalstereoscopic image. A UHD image generally has a number of horizontal andvertical pixels ranging from 4000 level (4 k·3840×2160) to 8000 level (8k·7680×4320). Since image resolution depends upon the number of pixels,the 4 k-based UHD image is four times clearer than an HD image (2k·1920×1080). The 8 k-based UHD image is sixteen times clearer than theHD image. The HD image has a refresh rate, i.e. the number of frames persecond, of 30 Hz. In the UHD image, on the other hand, 60 images aretransmitted per second, thereby realizing much more natural and dynamicimages.

In the multi-view broadcast, two images, such as top and bottom imagesor left and right images, having angles different according to a users'viewing angle are combined such that the users view a 3-D stereoscopicimage. In a case in which a television is provided with a multi-viewdisplay device, a left person views a left face of a performer and aright person views a right face of the performer when the performerappears on a screen. That is, the multi-view broadcast is an advancedtype of the 3-D stereoscopic broadcast.

The present invention proposes a method of selecting a transmission modesuitable to perform a new broadcast while maintaining compatibility withan existing broadcast channel when using any one selected from among the3-D stereoscopic broadcast, the UHD TV broadcast, and the multi-viewbroadcast.

Hereinafter, a frame-compatible mode, which is one of the transmissionmodes, will be described first and then a service-compatible mode, whichis another of the transmission modes, will be described.

FIG. 2A shows a frame-compatible mode and FIG. 2B shows examples ofmethods of synthesizing images to configure the frame-compatible mode.FIGS. 2A and 2B show an example of a 3-D stereoscopic broadcast.However, the present invention may be extended to a UHD TV broadcast anda multi-view broadcast in a similar manner. Hereinafter, theframe-compatible mode will be described in detail with reference toFIGS. 2A and 2B.

Referring to FIG. 2B, a frame containing combined left and right imagesis transmitted through a transmission band in the frame-compatible mode.Consequently, a transmission and reception form identical to a form usedin a conventional HD broadcast may be maintained. However, the broadcastin the frame-compatible mode is different from the conventional HDbroadcast in that the conventional HD broadcast transmit a video to theentire region but the broadcast in the frame-compatible mode transmitsan image synthesized based on the number of images. That is, as shown inFIG. 2B, a left image and a right image may be synthesized into a frameusing various methods. As shown in FIG. 2B(a), a frame may be dividedinto two halves and then synthesized. As shown in FIG. 2B(b), a framemay be divided in pixel steps and then synthesized. Alternatively, asshown in FIG. 2B(c), left and right images may be sequentiallytransmitted while a frame is maintained. In FIGS. 2B(a) and 2B(b), aspecific number of images are synthesized into a frame; therefore, aprocess of reducing each image is necessary. In FIG. 2B(c), a frame-rateis increased; therefore, it is necessary to increase a bandwidth or toadjust a video compression bitrate. There are various methods ofsynthesizing images. In the 3-D stereoscopic image as shown in FIG. 2B,the left image and the right image may be changed or the images may bemixed in diagonal pixel steps.

In the 3-D stereoscopic broadcast, for example, both the left image andthe right image are transmitted through one transmission band.Consequently, the 3-D stereoscopic broadcast has an half lower imageresolution than in a case in which an image frame is transmitted withthe result that image quality is deteriorated (FIGS. 2B(a) and 2B(b)).Otherwise, much more data must be transmitted in the same bandwidth. Tothis end, it is necessary to increase a compression rate with the resultthat image quality is deteriorated or a frame rate is lowered (FIG.2B(c)).

FIG. 3 shows a service-compatible mode. Hereinafter, theservice-compatible mode will be described in detail with reference toFIG. 3. FIG. 3 shows an example of a 3-D stereoscopic broadcast.However, the present invention may be extended to a UHD TV broadcast anda multi-view broadcast in a similar manner.

Referring to FIG. 3, a left image frame and a right image frame areindividually compressed and transmitted through a transmission bandwithout image synthesis in the service-compatible mode. That is, asshown in FIG. 3, the left image frame and the right image frame arecompressed using corresponding compression methods and the compressedleft image frame and right image frame are transmitted through onetransmission band. In order to transmit two or more compressed imagesthrough a limited transmission band, one of the image is compressed soas to be compatible with an existing HD broadcast, whereas the otherimage is transmitted while being coded using a compression method havinga higher compression rate. Alternatively, one of the left and rightimages is transmitted in a high resolution state and the other image istransmitted in a low resolution state. As an example, the left image istransmitted while being coded using MPEG-2 Main profile and the rightimage is transmitted while being coded using MPEG-4 AVC/H.264 Highprofile. In a case in which low resolution is used, an image stream ofthe left image is transmitted at a resolution of 1080i@60 Hz using theabove coding method and an image stream of the right image istransmitted at a resolution of 720p@60 Hz using the above coding method.In addition, the right image is sub-sampled in the vertical orhorizontal direction while the left image is not changed and a receivingunit restores the sampled right image so as to correspond to theresolution of the left image to form one stereoscopic image.

When a new broadcast is performed while maintaining compatibility withan existing broadcast channel in the digital broadcast as describedabove, a transmission mode of a composite broadcast is divided into aframe-compatible mode and a service-compatible mode. An transmission endtransmits a compressed image to a receiving end using one of the twotransmission modes. The receiving end must recognize the transmissionmode used by the transmission end to decode the received compressedimage. An existing broadcast receiving system that is not capable ofprocessing the composite images disregards a secondary video of thereceived composite images and reproduces only a primary video of thereceived composite images. Consequently, it is possible to selectivelyreceive the composite broadcast while maintaining compatibility with theexisting broadcast channel.

In an embodiment of the present invention, a receiving system that iscapable of processing a 3D image receives identification information torecognize the reception of a 3D image while the identificationinformation is contained in system information. Program SpecificInformation/Program and System Information Protocol (PSI/PSIP) isapplied as system information; however, the present invention is notlimited thereto. That is, any protocol transmitting system informationas a table format may be applied to the present invention irrespectiveof the term thereof.

PSI is a system standard of MPEG-2 defined to classify channels andprograms. PSIP is a standard of Advanced Television Systems Committee(ATSC) that is capable of classifying channels and programs.

In an embodiment, PSI may include a Program Association Table (PAT),Conditional Access Table (CAT), Program Map Table (PMT), and NetworkInformation Table (NIT).

PAT is specific information transmitted by a packet having a PID of 0.PID information of PMT and PID information of NIT are transmitted foreach program by using the PAT. CAT transmits information regarding acharged broadcast system used by the transmission side. PMT transmitsPID information of a transport stream packet to transmit individualbitstreams of video and audio constituting a program, programidentification number and PID information to transmit PCR. NIT transmitsinformation of a real transmission network. For example, a PAT tablehaving a PID of 0 is parsed to find program number and PID of PMT. PMTobtained from PAT is parsed to know a correlation between componentsconstituting the program.

FIG. 4 is a view showing the structure of a program map table (PMT)syntax according to an embodiment of the present invention. Hereinafter,the structure of a program map table (PMT) syntax according to anembodiment of the present invention will be described in detail withreference to FIG. 3.

Referring to FIG. 4, a table_id field is a table identifier. Anidentifier to identify PMT may be set. A section_syntax_indicator fieldis an indicator to define a section form of PMT. A section_length fieldindicates the section length of PMT.

A program_number field indicates program number as informationcoinciding with PAT. A version number field indicates version number ofPMT. A current_next_indicator field is an indicator to indicate whetherthe current table section is applicable.

A section_number field indicates section number of the current PMTsection when PMT is transmitted while being divided into one or moresections. A last_section_number field indicates last section number ofPMT. A PCR PID field indicates PID of a packet that transmits programclock reference (PCR) of the current program.

A program_info_length field indicates length information of descriptorsfollowing the program_info_length field in bytes. That is, theprogram_info_length field indicates length of descriptors included in afirst loop. A stream_type field indicates coding information and type ofan elementary stream included in a packet having a PID value indicatedby the following elementary_PID field. A elementary_PID field indicatesan identifier of the elementary stream, i.e. a PID value of a packetincluding the elementary stream. An ES_Info_length field indicateslength information of descriptors following the ES_Info_length field inbytes. That is, the ES_Info_length field indicates length of descriptorsincluded in a second loop.

In addition, referring to FIG. 4, a descriptor related to synthesisinformation regarding left and right images for specific program number,i.e. a descriptor related to a transmission mode, is present in adescriptor following a program_info_length syntax. In addition, adescriptor related to individual ESs of left and right images is presentin a descriptor following an ES_info_length syntax. Referring to FIG. 3,the descriptor related to synthesis information regarding left and rightimages is defined as service_compatible_stereoscopic_video_descriptorQ.Information related to frame packing arrangement describesMPEG2_video_(—)3d-frame_packing_arrangement_descriptor( ) defined in theframe-compatible mode. The descriptor related to the individual ESs ofleft and right images is defined as stereoscopic_stream_descriptor( ).Referring to FIG. 4, however, these descriptors are directly expressedin the syntax to indicate the positions of the descriptors. In fact,however, the descriptors are selectively included like conventionaldescriptors.

Referring to FIG. 4, the descriptor related to synthesis informationregarding left and right images for specific program number is firstconfigured and then the descriptor related to individual ESs of left andright images is configured; however, the present invention is notlimited thereto. That is,MPEG2_video_(—)3d_frame_frame_packing_arrangement_descriptor( ) may notbe located at the current position but at a descriptor underES_info_length. This is because one video PID is provided in theframe-compatible mode; therefore, the PID is present together with thedescriptor. The positions of the descriptors of FIG. 4 may be variableas the position ofMPEG2_video_(—)3d_frame_frame_packing_arrangement_descriptor( ) isvariable.

Hereinafter, a method of providing a descriptor related to synthesis ofcomposite images will be described. The method of providing thedescriptor related to synthesis of the composite images includes amethod using stream type, a method using presence and absence of thedescriptor, and a method of confirming a frame-compatible mode flag. Ofcourse, a descriptor related to synthesis of left and right images maybe provided using methods other than the above methods.

First, a method using stream type will be described. Table 1 belowillustrates stream type for a 3D stereoscopic broadcast in PSI.

TABLE 1 Value Description Ox00 ITU-T/ISO/TEC Resrved Ox01 ISO/IEC11172-2 Video Ox02 ITU-T Rec H.262/ISO/IEC 13818-2 Video OR ISO/IEC11172-2 constrained parameter video stream Ox03 ISO/IEC 11172-3 VideoOx04 ISO/IEC 13818-3 Video . . . . . . Ox0A ISO/IEC 13818-8 type A . . .. . . Ox22 ITU-T Rer. H.262/ISO/IEC 13818-2 Video with stereoscopiccount coded using frame-compatible mode Ox23 ITU-T Rer. H.262/ISO/IEC13818-2 Video with stereoscopic count coded using service-compatiblemode . . . . . . Ox80-OxFF User Private

A descriptor related to synthesis of left and right images is providedusing stream type indicated in Table 1. That is, if stream type is Ox02,it indicates a 2D image. If stream type is Ox22 and Ox23, it indicates a3D stereoscopic image. For example, if stream type is Ox22, it indicatesa frame-compatible mode. If stream type is Ox23, it indicates aservice-compatible mode.

Consequently, a receiving end may confirm the stream type of thereceived PSI to distinguish between the frame-compatible mode and theservice-compatible mode. In addition, the receiving end may receive adescriptor related to synthesis of left and right images.

The second method is a method using presence and absence of thedescriptor. That is, if a descriptor related to a frame-compatible modeis present, it means that the corresponding image is transmitted in theframe-compatible mode. If a descriptor related to a service-compatiblemode is present, it means that the corresponding image is transmitted inthe service-compatible mode. That is, the second method provides adescriptor related to synthesis of left and right images using presenceor absence of a descriptor related to a specific mode. Referring to FIG.4, if a descriptor for the service-compatible mode, such asservice_compatible_stereoscopic_video_descriptorQ, is present in a 3Dstereoscopic broadcast, the service-compatible mode is distinguished. Ifa descriptor for the frame-compatible mode, such asMPEG2_video_(—)3d-frame_packing_arrangement_descriptor( ) is present,the frame-compatible mode is distinguished.

The third method is a method of confirming a frame-compatible mode flag.That is, a frame-compatible mode flag is confirmed to provide adescriptor related to synthesis of composite images.

Table 2 indicates an example of a frame-compatible mode flag of a 3Dstereoscopic broadcast according to an embodiment of the presentinvention.

TABLE 2 MPEG2_video_3d_stereoscopic_descriptor{    descriptor_tag  descriptor_length   { syntaxes common to modes }  frame_compatible_mode_flag  If (frame_compatible_mode_flag){   {syntaxes for Frame-Compatible mode }  }  else {   { syntaxes forService-Compatible mode }  } }

As indicated in Table 2, a frame_compatible_mode_flag syntax may beprovided and divided into detailed syntaxes in the descriptor accordingto supporting methods. Consequently, the syntax in the descriptor may bedivided into {syntaxes common to modes}, {syntaxes for Frame-Compatiblemode}, and {syntaxes for Service-Compatible mode}. As described above,the third method provides a descriptor related to synthesis of compositeimages using a descriptor flag. Of course, a service-compatible flag maybe defined and used instead of the frame-compatible flag according tocircumstances. Alternatively, a method of additionally assigning a modebit (for example, a frame-compatible mode if the mode bit is 1 and aservice-compatible mode if the mode bit is 2 may be used instead ofusing the flag. However, these methods are included in technology fordivision into the frame-compatible mode and the service-compatible mode.

FIG. 5 is a view showing a procedure of the PMT. Hereinafter, aprocedure of the PMT will be described with reference to FIG. 5.

At S500, a PMT length is confirmed using section_length.

At S502, a syntax including program_number is read.

At S504, a descriptor length is confirmed using program_info_length.

At S506, it is confirmed whether all descriptors related to program infohave been read. If all descriptors have been read, the procedure movesto S510. If all descriptors have not been read, the procedure moves toS508, where one descriptor related to program info is read.

At S510, it is confirmed whether the PMT has been completely read. Ifthe PMT has been completely read, the procedure moves to S510. If thePMT has not been completely read, the procedure moves to S512. At S512,stream_type and elementary_PID are read.

At S514, a descriptor length is confirmed using ES_info_length.

At S516, it is confirmed whether all descriptors related to ES info havebeen read. If all descriptors have been read, the procedure moves toS518. If all descriptors have not been read, the procedure moves toS520.

At S520, one descriptor related to ES info is read and the proceduremoves to S516. At S518, CRC_(—)32 is read and a data error is verified.

FIG. 6 is a flowchart showing a process of providing a descriptorrelated to synthesis of left and right images using stream typeaccording to an embodiment of the present invention. Hereinafter, aprocess of providing a descriptor related to synthesis of left and rightimages using stream type according to an embodiment of the presentinvention will be described with reference to FIG. 6.

At S600, a PMT length is confirmed using section_length.

At S602, a syntax including program_number is read.

At S604, a descriptor length is confirmed using program_info_length.

At S606, it is confirmed whether all descriptors related to program infohave been read. If all descriptors have been read, the procedure movesto S610. If all descriptors have not been read, the procedure moves toS608, where one descriptor related to program info is read.

At S610, it is confirmed whether the PMT has been completely read. Ifthe PMT has been completely read, the procedure moves to S628. If thePMT has not been completely read, the procedure moves to S612. At S612,stream_type and elementary_PID are read.

At S614, it is confirmed whether stream type is 0x22. If stream type is0x22, the procedure moves to S616. If stream type is not 0x22, theprocedure moves to S618.

At S616, a Frame-Compatible mode is activated.

At S618, it is confirmed whether stream type is 0x23. If stream type is0x23, the procedure moves to S620. If stream type is not 0x23, theprocedure moves to S622.

At S620, a Service-Compatible mode is activated.

At S622, a descriptor length is confirmed using ES_info_length.

At S624, it is confirmed whether all descriptors related to ES info havebeen read. If all descriptors have been read, the procedure moves toS610. If all descriptors have not been read, the procedure moves toS626.

At S626, one descriptor related to ES info is read and the proceduremoves to S624. At S628, CRC_(—)32 is read and a data error is verified.

FIG. 7 is a flowchart showing a process of providing a descriptorrelated to synthesis of left and right images using presence and absenceof a descriptor according to an embodiment of the present invention.Hereinafter, a process of providing a descriptor related to synthesis ofleft and right images using presence and absence of a descriptoraccording to an embodiment of the present invention will be describedwith reference to FIG. 7.

At S700, a PMT length is confirmed using section_length.

At S702, a syntax including program_number is read.

At S704, a descriptor length is confirmed using program_info_length.

At S706, it is confirmed whether all descriptors related to program infohave been read. If all descriptors have been read, the procedure movesto S710. If all descriptors have not been read, the procedure moves toS708, where one descriptor related to program info is read.

At S710, it is confirmed whether the PMT has been completely read. Ifthe PMT has been completely read, the procedure moves to S720. If thePMT has not been completely read, the procedure moves to S712. At S712,stream_type and elementary_PID are read. At S714, a descriptor length isconfirmed using ES_info_length.

At S716, it is confirmed whether all descriptors related to ES info havebeen read. If all descriptors have been read, the procedure moves toS710. If all descriptors have not been read, the procedure moves toS718.

At S718, one descriptor related to ES info is read and the proceduremoves to S716. At S720, CRC_(—)32 is read and a data error is verified.

At S722, it is confirmed whether a descriptor for Frame-Compatible ispresent. If a descriptor for Frame-Compatible is present, the proceduremoves to S724, where a Frame-Compatible mode is activated.

If a descriptor for Frame-Compatible is not present, the procedure movesto S726, where it is confirmed whether a descriptor forService-Compatible is present. If a descriptor for Service-Compatible ispresent, the procedure moves to S728, where a Service-Compatible mode isactivated.

FIG. 8 is a flowchart showing a process of providing a descriptorrelated to synthesis of left and right images using a frame-compatiblemode flag according to an embodiment of the present invention.Hereinafter, a process of providing a descriptor related to synthesis ofleft and right images using a frame-compatible mode flag according to anembodiment of the present invention will be described with reference toFIG. 8.

At S800, a PMT length is confirmed using section_length.

At S802, a syntax including program_number is read.

At S804, a descriptor length is confirmed using program_info_length.

At S806, it is confirmed whether all descriptors related to program infohave been read. If all descriptors have been read, the procedure movesto S820. If all descriptors have not been read, the procedure moves toS808, where one descriptor related to program info is read.

At S810, it is confirmed whether the read descriptor is a descriptorregarding plural images (3D, UD, and MV). If the read descriptor is adescriptor regarding plural images, the procedure moves to S812. If theread descriptor is not a descriptor regarding plural images, theprocedure moves to S806.

At S812, frame-compatible_mode_flag is confirmed. At S814, aFrame-Compatible mode is confirmed. If the Frame-Compatible mode isconfirmed, the procedure moves to S816. Otherwise, the procedure movesto S818.

At S816, a Frame-Compatible mode is activated. At S818, aService-Compatible mode is activated.

At S820, it is confirmed whether the PMT has been completely read. Ifthe PMT has been completely read, the procedure moves to S830. If thePMT has not been completely read, the procedure moves to S822. At S822,stream_type and elementary_PID are read.

At S824, a descriptor length is confirmed using ES_info_length.

At S826, it is confirmed whether all descriptors related to ES info havebeen read. If all descriptors have been read, the procedure moves toS810. If all descriptors have not been read, the procedure moves toS828.

At S828, one descriptor related to ES info is read and the proceduremoves to S826. At S830, CRC_(—)32 is read and a data error is verified.

Although the above description is focused on a 3D stereoscopicbroadcast, which is being currently tested and broadcast standards ofwhich are under establishment, broadcasting in the frame-compatible modeand in the service-compatible mode may be performed in other compositebroadcasts, such as a UHD TV broadcast and a multi-view broadcast.Consequently, the present invention is applicable to other compositebroadcasts, such as a UHD TV broadcast and a multi-view broadcast, aswell as a 3D stereoscopic broadcast.

Although the present invention has been described with reference to theembodiments shown in the drawings, the embodiments are illustrative.Therefore, those skilled in the art will appreciate that various andequivalent modifications may be embodied from the above embodiments.

1. A method of processing a three-dimensional (3D) service in a digitalbroadcast receiver, the method comprising: receiving a transport stream(TS) including a Program Association Table (PAT); parsing the PAT basedon a predefined packet identifier (PID) from the received TS; acquiringa Program Map Table (PMT) based on a PMT_PID field included in theparsed PAT; and processing the acquired PMT including a stream_typefield and multiple descriptors associated with 3D service, wherein abase view video of service-compatible stereoscopic 3D services issignaled using the stream_type value 0x02, further an additional viewvideo for service-compatible stereoscopic 3D services is signaled usingthe stream_type value 0x22 or 0x23, wherein a first descriptor among themultiple descriptors associated with 3D service comprises informationidentifying whether the stereoscopic 3D service included in the receivedTS is either a frame-compatible stereoscopic 3D service or aservice-compatible stereoscopic 3D service, and wherein a seconddescriptor among the multiple descriptors associated with 3D serviceprovides information related to the service-compatible stereoscopic 3Dservice, further the second descriptor is included for both the baseview video and the additional view video in the PMT for programs thatsupport the service-compatible stereoscopic 3D service, the additionalview video's stream type value being 0x22 or 0x23.
 2. The method ofclaim 1, wherein the second descriptor comprised upsampling data definesa resolution relationship between a right view resolution and a leftview resolution of the stereoscopic 3D service.
 3. The method of claim2, wherein the upsampling data defines a value of the right viewresolution which is different with a value of the left view resolutionand the value of the right view resolution has a value from one of ¾, ⅔and ½ of the left view resolution.
 4. The method of claim 1, wherein thefirst descriptor and the second descriptor are located in the PMTdifferently from each other.
 5. The method of claim 4, wherein the firstdescriptor is located in a loop of a program_info_length field of thePMT and the second descriptor is located in a loop of an ES_info_lengthfield of the PMT.
 6. A digital broadcast receiver for processing athree-dimensional (3D) service, the digital broadcast receivercomprising: a tuner configured to receive a transport stream (TS)including a Program Association Table (PAT); and a controller configuredto parse the PAT based on a predefined packet identifier (PID) from thereceived TS, acquire a Program Map Table (PMT) based on a PMT_PID fieldincluded in the parsed PAT, and process the acquired PMT including astream_type field and multiple descriptors associated with 3D service,wherein a base view video of service-compatible stereoscopic 3D servicesis signaled using the stream_type value 0x02, further an additional viewvideo for service-compatible stereoscopic 3D services is signaled usingthe stream_type value 0x22 or 0x23, wherein a first descriptor among themultiple descriptors associated with 3D service comprises informationidentifying whether the stereoscopic 3D service included in the receivedTS is either a frame-compatible stereoscopic 3D service or aservice-compatible stereoscopic 3D service, and wherein a seconddescriptor among the multiple descriptors associated with 3D serviceprovides information related to the service-compatible stereoscopic 3Dservice, further the second descriptor is included for both the baseview video and the additional view video in the PMT for programs thatsupport the service-compatible stereoscopic 3D service, the additionalview video's stream type value being 0x22 or 0x23.
 7. The digitalbroadcast receiver of claim 6, wherein the second descriptor comprisedupsampling data defines a resolution relationship between a right viewresolution and a left view resolution of the stereoscopic 3D service. 8.The digital broadcast receiver of claim 7, wherein the upsampling datadefines a value of the right view resolution which is different with avalue of the left view resolution and the value of the right viewresolution has a value from one of ¾, ⅔ and ½ of the left viewresolution.
 9. The digital broadcast receiver of claim 6, wherein thefirst descriptor and the second descriptor are located in the PMTdifferently from each other.
 10. The digital broadcast receiver of claim9, wherein the first descriptor is located in a loop of aprogram_info_length field of the PMT and the second descriptor islocated in a loop of an ES_info_length field of the PMT.